1. Field of the Invention
The present invention concerns a flame mitigation device for portable containers, which are configured to hold and dispense flammable liquid fuels. More particularly, embodiments are concerned with a flame mitigation device, which is configured to allow liquid fuel to pass through at a rate sufficient to prevent spillage during filling at standard gas pump flow rates and to inhibit explosions by retaining fuel sufficient to provide a fuel-air mixture that is too rich to support combustion.
2. Description of the Prior Art
Portable fuel containers as used herein are intended to refer to containers which hold about 6 gallons (about 26.43 liters) or less of fuel. Such portable fuel containers have traditionally been constructed of metal or synthetic resin and configured to permit stored fuel to be dispensed from an opening for use. Existing portable fuel containers are safe and effective for their intended purpose when properly used. Unfortunately, notwithstanding warning labels, common sense and safety instruction, as well as the experiences of others, users are known to have improperly used fuel containers. Bad judgment or practically no judgment is occasionally exercised by those users who ignore safe practices and instead recklessly pour liquid fuel from a portable container into a smoldering campfire or brush pile, or even onto an open flame. The resulting consequences are predictable but tragic when the fuel which is being poured and the fuel vapors ignite and burns the user and others in the vicinity of the fuel container.
Most children are taught at a young age that fire or explosion may result from a combination of fuel (e.g., gasoline or other inflammable liquids), oxygen (such as is present in the atmosphere) and a source of ignition. Most safety measures concentrate on eliminating one of these elements. Thus, modern EPA approved portable fuel containers include warnings and provide closures that enclose the fuel container to shut off the source of fuel. These fuel containers work well under normal circumstances where the user exercises even a minimum of care. It is believed that even under conditions of abuse as described herein, fuel containers of recent manufacture will not explode. However, explosions within fuel containers have been induced by researchers in highly-controlled, extreme laboratory environments. While it is believed that it is only possible to produce an explosion within a fuel container under such extreme laboratory conditions, there has developed a need for a new approach to inhibiting combustion within portable fuel containers.
Attempts have been made to eliminate the possibility of portable fuel container explosions. Some portable fuel containers made of metal (specifically safety cans) employ a metal flame arrestor. A flame arrestor is a metal screen that is fitted inside the neck of the tank and attempts to keep an ignition source such as a flame or spark from entering the tank of the portable fuel container. While such flame arrestors may be beneficial in a safety can, there are difficulties using them in common plastic fuel containers. For example, while filling a portable fuel container at a gas station, pumping gasoline through a flame arrestor screen could cause the fuel to splash back out of the container and mix with air, thereby creating a mixture ready for combustion. Moreover, pumping gasoline through a metal screen may cause a static spark with obvious catastrophic consequences. Metal safety cans offer a grounding tab to prevent this static electricity discharge, but this is not possible nor practical in a synthetic resin (plastic) tank as ordinary consumers are not familiar with this apparatus or practice. Furthermore, the presence of a metal flame arrestor may give the user a false sense of security or safety to the consumer and user and, if positioned just inside the neck of the container (as they are in such metal safety cans) they can be easily removed, thus defeating the intent of protecting against even irresponsible use.
Thus, while the use of existing flame arrestors may have benefits, its limitations, especially in the context of use in a synthetic resin portable fuel container, still presents problems and far outweigh any benefits. A flame arrestor's intent is to keep the flame or spark from entering a portable fuel container, but this may not prove sufficient to defeat combustion when a user removes the flame arrestor or pours fuel directly onto fire.
Some attempted solutions for the aforementioned problems have been further complicated when liquid fuel cannot be received in the fuel container at a fast-enough rate to prevent spillage during filling at standard gas pump flow rates. Moreover, it has heretofore been difficult to securely couple previously-used flame arrestors, or other flame mitigation devices, to the fuel container.